Air duct



FIG. 1 is a perspective view taken from the front, top and right side ofthe air duct showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a front elevational view thereof, the rear elevational viewbeing a mirror image to the front elevational view;

FIG. 5 is a right side elevational view thereof, the left sideelevational view being a mirror image to the right side elevationalview; and,

FIG. 6 is a top plan view thereof with the small diameter cylinderinside the air duct turned 90 degrees;

FIG. 7 is a top plan view thereof with the large diameter cylinderinside the air duct turned 90 degrees; and,

FIG. 8 is a vertical cross sectional front view of the air duct takenalong line 8--8 in FIG. 1.

The ornamental design for an air duct, as shown and described.